Valve

ABSTRACT

A valve is provided with a rotatable spool which has a bypass position to bypass incoming fluid from pump directly to the tank, a forward position to direct incoming fluid to one working port and return the fluid from another working port to tank, and a third position to direct the incoming fluid in the opposite direction through the two working ports. The position of the spool can also be adjusted to provide excellent flow metering characteristics.

United States Patent Bliss VALVE [76] Inventor: George N. Bliss, Box 1,

Renton, Wash. 98055 [22] Filed: Mar. 12, 1973 [21] Appl. No.: 340,202

[521 US. Cl. l37/625.24 [51] Int. Cl Fl6k 11/02 [58] Field of Search.....-l37/625.2l, 625.22, 625.23,

[56] References Cited UNITED STATES PATENTS 2,985,147 5/1961 Rockwell 137/625.68 X 3,015,344 l/1962 Hausmann et al. l37/625.23 3,430,653 V 3/1969 Brimhall 137/625.23

[ June 11, 1974 3,443,593 5/1969 Colombo l37/625.24 3,610,283 l0/l97l Hill et al. l37/625.23

Primary Examiner-Henry T. Klinksiek 57 ABSTRACT 7 Claims, 11 Drawing Figures VALVE BACKGROUND OF TI-IEINVENTION 1. Field of the Invention This invention pertains to hydraulic directional flow control valves.

2. Summary of the Invention It is an object of this invention to provide a hydraulic directional flow control valve that is inexpensive to manufacture.

It is another object of this invention to provide a hydraulic directional flow control valve that has excellent metering characteristics, and is positionable for bypassing, or moving fluid in forward or reverse directions through working ports.

Basically, these objects are obtained by using a valve block having a spool opening, a rotatable spool positioned in the opening, means for rotating the spool into three different positions, means in the spool when in a bypass position inter-connecting first inlet and outlet ports of the block and blocking second inlet and outlet ports, means in the spool when the spool is in a forward position for inter-connecting said first inlet port with said second inlet port and inter-connecting said first outlet port with said second outlet .-port, and means in said spool when the spool is in the reverseposition for inter-connecting said first inlet port with said second outlet port and for inter-connecting said first outlet port with said second inlet port. In both forward and reverse positions the spool can be rotated to efiect smoothmetering characteristics. Having very few ports which can be cast in place or drilled the valve is inexpensive to manufacture and simple to operate.

In thepreferred embodiment of the valve the spool in its normal non-working condition provides a bypass between pump and tank. By reversing the position of the valve block relative to the pump and tank the valve can become a closed center spool valve to block all ports from each other when in its normal center position. In both cases the valve is considered to be a 3- position 4-way valve with two paths of flow in each of the two extreme positions.

The preferred embodiments of the valve have a block and spool port configuration in which the bypass openings of the spool and block overlap the forward or reverse ports. In this manner moving the valve core from the top dead-center bypass position into either the forward or reverse position will immediately begin flow in the selected direction while maintaining substantial bypass fiow and with further movement from the top dead-center position will increase the flow in the particular direction while reducing bypass flow until bypass is blocked completely. It is this overlap of the ports which assures smooth metering of the flow from zero directional flow to maximum directional flow. In short, the valve has a very wide range of speed control either forwarder reverse from the bypass position.

Another advantage of the preferred embodiments is that the ports from tank and pump and the two working ports are on flat surfaces and are longitudinally spaced from one another on these surfaces so that the valve can be fastened directly to a wide range of hydraulic machinery-For example, a preferred use of the valve is to connect it directly to a conventional hydraulic motor without a special adaptor or without hydraulic lines between the valve and the motor. This advantageously reduces leakage problems and provides a more compact control mechanism for the motor.

BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWINGS FIG. 1 is an isometric of the valve embodying the principles on the invention.

FIG. 2 is a front elevation of the valve shown in FIG. 1.

FIG. 3 is a side elevation of the valve shown in FIG. 1.

FIG. 4 is an isometric of the spool employed in the valve shown in FIG. 1.

FIG. 5 is a transverse section of the spool in FIG. 4.

FIGS. 6, 7, and 8 are longitudinal sections of the spool taken along the section lines 6, 7, and 8 of FIG. 4.

FIGS. 9. 10. and 11 are operational diagramatic illustrations corresponding to the spool positions shown respectively in FIGS. 6, 7, and 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1 the valve embodying the principles of this invention includes a spool 21, and a body or block 10 having a first inlet or pump port 12 and a first outlet or tank port 14. The valve also has second inlet or working portl6 and second outlet or working port 18. The ports 12 and 14 are aligned on the same plane. Similarly the ports 16 and 18 are also on a plane. The ports 16 and 18 in the preferred embodiment are spaced longitudinally from one another relative to the spool axis of rotation making them readily adaptable alignable with the inlet ports of a conventional hydraulic motor. Thus, the valve can be easily mounted directly to the motor housing if desired. The valve is provided with a spool opening 20 which intercepts the ports 12, 14, 16, and 18. I 2

The terms inlet and outlet employed in this application for designating the various ports can be used interchangeably. For example, if port 12 is connected to the pump and port 14 to a tank it is obvious that they can be reversed so that port 14 becomes the pump connection and port 12 becomes the tank connection. As will also be discussed hereinbelow port 16 can be made the pump connection and correspondingly the opposite port 18 can be made the pump connection or vice versa so that the valve can be used as a closed center position valve rather than a bypass center position valve as in the preferred embodiment. The convention of using ports 16 and 18 as working ports and ports 12 and 14 as pump and tank ports, respectively, will be followed in the remainder of the application for purposes of clarity. But it should be understood that the invention is not to be limited to such a configuration.

As best shown in FIGS. 2 and 3, the first inlet port 12 has a main passage 12a and a secondary passage 12b longitudinally spaced from the main passage along the axis of rotation of the spool 21. Likewise port 14 has a main passage 14a and-a secondary passage 14b. The passage 14b is spaced longitudinally along the axis of rotation of spool 21 from the main passage 14a and lies between the main 12a and secondary 12b passages of the first inlet port 12. In the preferred embodiment, the first outlet secondary passage 14a connects with the first outlet main passage 14b by a drilled hole 14c.

However, it should be understood that all of the ports in the block can be cast if desired.

Ports 16 and 18 are joined if desired by conventional relief check valves 24 and 26. Although not necessary for operation of the valve it may be desirable to add this pressure relief internally in the valve if external pressure relief is not provided in the system.

The spool 21 is best illustrated in FIGS. 4-8. The spool is provided with a lock ring recess 28 adapted to receive a locking clip to hold the spool in the block in a well-known manner, and conventional sealing recesses 30 for holding typical O-ring seals or the like.'A handle 32 is provided for pivoting the spool about its longitudinal axis. The spool is provided with a milled bypass slot 34, which when the spool is in the center or bypass position, connects with FIGS. 12 and 14 as best shown in FIG. 9. The spool also includes a first main passage 36 and a second passage 38 which pass diametrically through the spool. Finally, the spool is provided with a first secondary passage 40 and a second secondary passage 42 which are inclined to the diameter of the spool and intercept with the passages 36 and 38.

In operation, the spool is moved from the center position shown in FIGS 6 and 9 to either the forward or reverse position. To move the spool to the reverse position the spool is rotated counter-clockwise, as shown in FIG. 1, to align passage 42 with ports 12b and 18 whereas passage 40 will become aligned with ports 14b and 16. Using the original convention this will run the motor M in the reverse direction. Moving the handle in the clock-wise direction will align passage 36 with ports 12a and 16 whereas passage 38 will be aligned with ports 14a and l8. Again using the original convention this will run the motor in the forward direction. It should be understood that the bypass slot 34 and the passages or ports in the spool and block overlap so that movement of the spool in either direction from its center bypass position will immediately begin to allow flow into the ports 16 and 18. Thus a limited rotation will provide a slow directional speed to the motor and increase rotation of the spool will eventually result in maximum directional flow to the motor.

As mentioned previously the ports 16 and 18 can be connected to the pump or tank. Conversely, the pump and tanks port 12 and 14 can be made the working ports connecting directly to the motor. In this configuration the center position of the spool thus blocks fiow from the pump to the tank. Movement of the spool in either direction will then result in directional flow to the motor from the blocked position.

While the preferred embodiments of the invention has been illustrated and described it should be understood that variations will be apparent to one skilled in the art without departing the principles of the invention. Accordingly the invention is not to be limited to the specific embodiments described.

1. A four-way valve comprising a block having a spool opening, first inlet and outlet ports, second inlet and outlet ports, a spool in said spool opening, means for rotating said spool into three different positions, means insaid spool when the spool is in a bypass position interconnecting said first inlet and outlet ports and blocking said second inlet and outlet ports, means in said spool when the spool is in a forward position for interconnecting said first inlet port with said second inlet port and interconnecting said first outlet port with said second outlet port, and means in said spool when the spool is in a reverse position for interconnecting said first inlet port with said second outlet port and for interconnecting said first outlet port with said second inlet port.

2. The valve of claim 1 said first inlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced locations along the spool axis of rotation, said first outlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced openings along the spool axis of rotation, said main and secondary passages of said first inlet and outlet ports being located at the spool opening along the axis of the spool as follows: first inlet main, first outlet secondary, first inlet secondary, first outlet main; in said spool forward position said first inlet main passage being connected with said second inlet port and said first outlet main passage being connected with said second outlet port, and in said spool reverse position said first inlet secondary passage being connected with said second outlet port and said first outlet secondary passage being connected with said second inlet port.

3. The valve of claim 2 said spool including a first main passage interconnectable with said first inlet main passage and said second inlet port in the spool forward position, a second main passage interconnectable with said first outlet main passage and said second outlet in the spool forward position, a first secondary passage interconnectable with the first outlet secondary passage and the second inlet port when in a spool reverse position, and a second secondary passage interconnectable with the first inlet secondary passage and the second outlet port when in aspool reverse position.

4. The valve of claim 3 said spool including a longitudinal recess for interconnecting said first inlet port, and first outlet port for a bypass between the two ports.

5. The valve of claim 1 said spool including a longitudinal recess for interconnecting said first inlet port and first outlet port.

6. The valve of claim 4 including relief means interconnecting said second inlet and outlet ports when excessive pressures are present.

7. A four-way valve comprising a block having a spool opening, first inlet and outlet ports, second inlet and outlet ports, a spool in said' spool opening, means for rotating said spool into at least two different positions, said first inlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced locations along the spool axis of rotation, said first outlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced openings along the spool axis of rotation, said main and secondary passages of said first inlet and outlet ports being located at. the

spool opening along the axis of the spool as follows: first inlet main, first outlet secondary, first inlet secondary, first outlet main; in a spool forward position said first inlet main passage being connected with said second inlet port and said first outlet main passage being connected with said second outlet port, and in a spool reverse position said first inlet secondary passage being connected with said second outlet port and said first outlet secondary passage being connected with said second inlet port.

iii 

1. A four-way valve comprising a block having a spool opening, first inlet and outlet ports, second inlet and outlet ports, a spool in said spool opening, means for rotating said spool into three different positions, means in said spool when the spool is in a bypass position interconnecting said first inlet and outlet ports and blocking said second inlet and outlet ports, means in said spool when the spool is in a forward position for interconnecting said first inlet port with said second inlet port and interconnecting said first outlet port with said second outlet port, and means in said spool when the spool is in a reverse position for interconnecting said first inlet port with said second outlet port and for interconnecting said first outlet port with said second inlet port.
 2. The valve of claim 1 said first inlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced locations along the spool axis of rotation, said first outlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced openings along the spool axis of rotation, said main and secondary passages of said first inlet and outlet ports being located at the spool opening along the axis of the spool as follows: first inlet main, first outlet secondary, first inlet secondary, first outlet main; in said spool forward position said first inlet main passage being connected with said second inlet port and said first outlet main passage being connected with said second outlet port, anD in said spool reverse position said first inlet secondary passage being connected with said second outlet port and said first outlet secondary passage being connected with said second inlet port.
 3. The valve of claim 2 said spool including a first main passage interconnectable with said first inlet main passage and said second inlet port in the spool forward position, a second main passage interconnectable with said first outlet main passage and said second outlet in the spool forward position, a first secondary passage interconnectable with the first outlet secondary passage and the second inlet port when in a spool reverse position, and a second secondary passage interconnectable with the first inlet secondary passage and the second outlet port when in a spool reverse position.
 4. The valve of claim 3 said spool including a longitudinal recess for interconnecting said first inlet port, and first outlet port for a bypass between the two ports.
 5. The valve of claim 1 said spool including a longitudinal recess for interconnecting said first inlet port and first outlet port.
 6. The valve of claim 4 including relief means interconnecting said second inlet and outlet ports when excessive pressures are present.
 7. A four-way valve comprising a block having a spool opening, first inlet and outlet ports, second inlet and outlet ports, a spool in said spool opening, means for rotating said spool into at least two different positions, said first inlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced locations along the spool axis of rotation, said first outlet port including interconnected main and secondary passages joining said spool opening at longitudinally spaced openings along the spool axis of rotation, said main and secondary passages of said first inlet and outlet ports being located at the spool opening along the axis of the spool as follows: first inlet main, first outlet secondary, first inlet secondary, first outlet main; in a spool forward position said first inlet main passage being connected with said second inlet port and said first outlet main passage being connected with said second outlet port, and in a spool reverse position said first inlet secondary passage being connected with said second outlet port and said first outlet secondary passage being connected with said second inlet port. 